The problems in Harold Walker’s latest essay, amusingly titled “The Facts of Life”, start with his very first line: Digital Modulation is usually a form of pulse modulation, of which, there are two types-Pulse Width and Pulse position. What about pulse amplitude modulation (PAM), phase shift keying (PSK) and frequency shift keying (FSK), just to mention a few others? All pulses are analyzed by ...

The multilevel inverter topology gives the advantages of usage in high power and high voltage application with reduced harmonic distortion without a transformer. This paper presents a comparative study of nine level diode clamped inverter for constant Switching frequency of sinusoidal Pulse width Modulation and sinusoidal Natural Pulse width Modulation with switching frequency Optimal Modulation.

Soft Switcing techniques have recently been applied in the design of dc-ac converters, in order to achive better performance, higher efficiency, and power density. One of the soft switching techniques uesd in inverters is resonant dc links. These topologies have some disadvantages such as irregular current peaks, large voltage peaks, uncotrollble pulse width, etc. Another soft switching method ...

In this paper, various novel pulse width modulation techniques are proposed, which can minimize the total harmonic distortion and enhances the output voltages from five level inverter to multilevel topologies. Multilevel inverters are important for power electronics applications such as flexible ac transmission systems, renewable energy sources, uninterruptible power supplies and active power f...

Wide-bandwidth measurements are necessary when testing electronically switched drfves. 7 b o dfficult pmblems are addressed the measurement of motor phase input power at low speed. with a high PWM modulation frequency and the measurement of small torque ripple (superlmposed on a large mean toque). In an electrlcdlY noisy envlronment. Extensive use Is made of dlgilal signal processing techniques...

The aim of this work is to evaluate the effectiveness of a Simple Tuning algorithm applied on a Fuzzy Pulse Width Modulation controller in a real situation with DC gear motors. The fuzzy logic model proposed to control motor’s no-load speed consists in 25 rules based on Mamdani Fuzzy Inference System. A hardware implementation and an interface are designed for controlling the plant. In addition...

The main topic of this paper is to examine the impact on induction machine magnetic noise of a new stator magnetic circuit design. This new design was developed in order to increase AC machine energetic performance by assembling non-segmented shifted grainoriented steel sheets which make it possible to reduce iron losses. Experimental results on induction machine efficiency increase are present...

The optimal torque control of a synchronous machine is a classical problem. This paper presents an alternative to SVM (Space Vector Modulation which belongs to PWM approaches) based upon direct boolean control. The result is a predictive method allowing an optimal torque control of the synchronous machine. A comparison between both approaches will be proposed . Copyright  2002 IFAC